(1S,2S)-(-)-1-苯基亚丙基环氧

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Unlike CF3COCH3, which gives higher conversion at high pH, acetone catalyzed epoxidation reactions proceeded at much faster rate at a lower pH (about 8.3). Because the decomposition of H2O2 was not very fast at this pH, the reaction can be done at room temperature. Although controlled experiment showed that significant amount of epoxidation also occurred in the absence of acetone at this pH (Payne epoxidation), the addition of acetone allowed the epoxidation to proceed much faster and gave higher conversion. For example, a 41% conversion of trans-β-methylstyrene was obtained in the absence of acetone after stirred at room temperature for 10 h. However, in the presence of acetone, an 83% yield of trans-β-methylstyrene oxide could be obtained after stirring for 5 h. Table 4 lists additional examples using acetone under similar conditions. the reaction can be done at room temperature gave higher conversion

反应条件: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Reaction at −10° C.: trans-β-methylstyrene (0.181 g, 1 mmol) was dissolved in acetonitrile/DMM (15 mL, ½, V/V). Buffer (10 mL, 0.05 M solution of Na2B4O7.H2O in 4×10−4 M aqueous Na2EDTA), tetrabutylammonium hydrogen sulfate (15 mg, 0.04 mmol), and ketone 1 (0.0774 g, 0.3 mmol) were added with stirring. The mixture was cooled to about −10° C. via a NaCl-ice bath. A solution of Oxone® (0.85 g, 1.38 mmol) in aqueous Na2EDTA (4×10−4 M, 6.5 mL) and a solution of K2CO3 (0.8 g, 5.8 mmol) in water (6.5 mL) were added dropwise separately over a period of 2 h (via syringe pumps or addition funnels). The reaction was then worked up by the same procedure as Method B to afford trans-β-methylstyrene oxide (0.126 g, 94% yield, 95.5% ee). Reaction at −10° C. (via syringe pumps or addition funnels)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a 100 mL three-neck round bottom flask, were added buffer (0.05 M Na2B4O7.10H2O in 4×10−4 M aq. Na2EDTA, 10 mL), acetonitrile (15 mL), trans-β-methylstyrene (0.118 g, 1 mmol), tetrabutylammonium hydrogen sulfate (0.015 g, 0.04 mmol), and ketone 1 (0.0774 g, 0.3 mmol). The reaction mixture was cooled by an ice bath. A solution of Oxone® (0.85 g, 1.38 mmol) in aq. Na2EDTA (4×10−4 M, 6.5 mL) and a solution of K2CO3 (0.8 g, 5.8 mmol) in water (6.5 mL) were added dropwise through two separate addition funnels over a period of 1.5 h (under this condition, the reaction pH is around 10.5. At this point, the reaction was immediately quenched by addition of pentane and water. The mixture was extracted with pentane (3×30 mL), washed with brine, dried over Na2SO4, purified by flash chromatography [the silica gel was buffered with 1% Et3N in pentane, pentane/ether (1/0 to 50/1, V/V) was used as eluent] to afford trans-β-methylstyrene oxide as colorless liquid (0.124 g, 93% yield, 92% ee). The reaction mixture was cooled by an ice bath separate addition funnels over a period of 1.5 h (under this condition the reaction pH is around 10.5 At this point, the reaction was immediately quenched by addition of pentane and water The mixture was extracted with pentane (3×30 mL) washed with brine dried over Na2SO4 purified by flash chromatography [the silica gel

反应条件: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Reaction at −10° C.: trans-β-methylstyrene (0.181 g, 1 mmol) was dissolved in acetonitrile/DMM (15 mL, ½, V/V). Buffer (10 mL, 0.05 M solution of Na2B4O7H2O in 4×10−4 M aqueous Na2EDTA), tetrabutylammonium hydrogen sulfate (15 mg, 0.04 mmol), and ketone 1 (0.0774 g, 0.3 mmol) were added with stirring. The mixture was cooled to about −10° C. (inside) (outside temperature was about −12° C. to −15° C.) via a NaCl-ice bath. A solution of Oxone® (0.85 g, 1.38 mmol) in aqueous Na2EDTA (4×10−4 M, 6.5 mL) and a solution of K2CO3 (0.8 g, 5.8 mmol) in water (6.5 mL) were added dropwise separately over a period of 2 h (via syringe pumps or addition funnels). The reaction was then worked up by the same procedure as Method B to afford trans-β-methylstyrene oxide (0.126 g, 94% yield, 95.5%ee). Reaction at −10° C. (via syringe pumps or addition funnels)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a 100 mL three-neck round bottom flask, were added buffer (0.05 M Na2B4O7.10H2O in 4×10−4 M aq. Na2EDTA, 10 mL), acetonitrile (15 mL), trans-β-methylstyrene (0.118 g, 1 mmol), tetrabutylammonium hydrogen sulfate (0.015 g, 0.04 mmol), and ketone 1 (0.0774 g, 0.3 mmol). The reaction mixture was cooled by an ice bath. A solution of Oxone® (0.85 g, 1.38 mmol) in aq. Na2EDTA (4×10−4 M, 6.5 mL) and a solution of K2CO3 (0.8 g, 5.8 mmol) in water (6.5 mL) were added dropwise through two separate addition funnels over a period of 1.5 h (under this condition, the reaction pH is around 10.5. It is recommended that both Oxone® and K2CO3 be added uniformly over 1.5 h). At this point, the reaction was immediately quenched by addition of pentane and water. The mixture was extracted with pentane (3×30 mL), washed with brine, dried over Na2SO4, purified by flash chromatography [the silica gel was buffered with 1% Et3N in pentane, pentane/ether (1/0 to 50/1, V/V) was used as eluent] to afford trans-β-methylstyrene oxide as colorless liquid (0.124 g, 93 yield, 92%ee). The reaction mixture was cooled by an ice bath separate addition funnels over a period of 1.5 h (under this condition the reaction pH is around 10.5 be added uniformly over 1.5 h) At this point, the reaction was immediately quenched by addition of pentane and water The mixture was extracted with pentane (3×30 mL) washed with brine dried over Na2SO4 purified by flash chromatography [the silica gel to afford

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Unlike CF3COCH3, which gives higher conversion at high pH, acetone catalyzed epoxidation reactions proceeded at much faster rate at a lower pH (about 8.3). Because the decomposition of H2O2 was not very fast at this pH, the reaction can be done at room temperature. Although controlled experiment showed that significant amount of epoxidation also occurred in the absence of acetone at this pH (Payne epoxidation), the addition of acetone allowed the epoxidation to proceed much faster and gave higher conversion. For example, a 41% conversion of trans-β-methylstyrene was obtained in the absence of acetone after stirred at room temperature for 10 h. However, in the presence of acetone, an 83% yield of trans-β-methylstyrene oxide could be obtained after stirring for 5 h. Table 4 lists additional examples using acetone under similar conditions. the reaction can be done at room temperature gave higher conversion